A035891 Coordination sequence for diamond structure D^+_30. (Edges defined by l_1 norm = 1.)

1, 0, 1800, 0, 541200, 0, 65520920, 0, 4296107040, 0, 177923724072, 0, 5119703270960, 0, 109262828065080, 536870912, 1814093339150400, 249644974080, 24305082449321800, 21968757719040, 270526359458466384

Offset

0,3

Links

Ray Chandler, Table of n, a(n) for n = 0..1000

J. H. Conway and N. J. A. Sloane, Low-Dimensional Lattices VII: Coordination Sequences, Proc. Royal Soc. London, A453 (1997), 2369-2389 (pdf).

Joan Serra-Sagrista, Enumeration of lattice points in l_1 norm, Inf. Proc. Lett. 76 (1-2) (2000) 39-44.

Index entries for linear recurrences with constant coefficients, signature (0, 30, 0, -435, 0, 4060, 0, -27405, 0, 142506, 0, -593775, 0, 2035800, 0, -5852925, 0, 14307150, 0, -30045015, 0, 54627300, 0, -86493225, 0, 119759850, 0, -145422675, 0, 155117520, 0, -145422675, 0, 119759850, 0, -86493225, 0, 54627300, 0, -30045015, 0, 14307150, 0, -5852925, 0, 2035800, 0, -593775, 0, 142506, 0, -27405, 0, 4060, 0, -435, 0, 30, 0, -1).

Maple

f := proc(m) local k, t1; t1 := 2^(n-1)*binomial((n+2*m)/2-1, n-1); if m mod 2 = 0 then t1 := t1+add(2^k*binomial(n, k)*binomial(m-1, k-1), k=0..n); fi; t1; end; where n=30.

Crossrefs

Sequence in context: A234203 A220058 A235898 * A069476 A179695 A375013

Adjacent sequences: A035888 A035889 A035890 * A035892 A035893 A035894

Keyword

nonn

Author

Joan Serra-Sagrista (jserra(AT)ccd.uab.es)

Extensions

Recomputed by N. J. A. Sloane, Nov 27 1998

Status

approved